CN104193167A

CN104193167A - Fluorphosphate glass, glass material for compression molding, optical element blank, optical element and glass formed body as well as manufacturing method of glass formed body

Info

Publication number: CN104193167A
Application number: CN201410381364.9A
Authority: CN
Inventors: 池西干男
Original assignee: Hoya Corp
Current assignee: Hoya Corp
Priority date: 2009-08-26
Filing date: 2009-08-26
Publication date: 2014-12-10
Anticipated expiration: 2029-08-26
Also published as: CN104193167B

Abstract

The invention provides a fluorphosphate glass. The fluorphosphate glass comprises the following components: 3%-25% by cation of P<5+>, more than 30% by cation and less than 40% by cation of Al<3+>, 0.5%-20% by cation of Li<+> and more than 65% by anion of F<->; the fluorphosphate glass has a liquid-phase temperature below 700 DEG C. The invention also provides a glass material for compression molding, an optical element blank, an optical element and a glass formed body as well as a manufacturing method of the glass formed body. The fluorphosphate glass has ultralow dispersivity and stability, and is preferably applicable to the glass material for compression molding, the optical element blank and the optical element.

Description

Fluorphosphate glass, glass material, optical element blank, optical element and glass forming body and manufacture method for compression molding

The application is divisional application, the international application no of its original application is PCT/JP2009/064885, international filing date is on August 26th, 2009, China national application number is 200980155631.8, entering entering of China national stage day is on July 28th, 2011, and denomination of invention is " fluorphosphate glass, the manufacture method of glass material, optical element blank, optical element and manufacture method thereof and glass forming body for compression molding ".

Technical field

The present invention relates to a kind of being suitable for as the fluorphosphate glass of the material of the optical elements such as lens, prism and filter.In addition, the invention still further relates to glass material for compression molding, optical element blank and optical element, its each self-contained described fluorphosphate glass; Its manufacture method; Manufacture method with glass forming body.

Background technology

Fluorphosphate glass has been used to the various application including chromatic aberration correction glass as the glass having features such as low dispersivity and anomalous dispersion.

An example of this fluorphosphate glass is disclosed by patent documentation 1.In the disclosed glass of claim 1 of patent documentation 1, introduce lithium (Li) even if composition is to obtain the viscosity that is also suitable for moulding in the time that glass temperature reduces, thereby reduce or prevent from occurring striped when by the glass ware forming of melting, and the rising of inhibition second-order transition temperature or liquidus temperature, the amount of aluminium (Al) composition is limited in below 30 positively charged ion %.

Prior art document

Patent documentation

Patent documentation 1:JP-A-2006-306706

Summary of the invention

The problem to be solved in the present invention

By above method, above-mentioned fluorphosphate glass has been realized high-quality in whole low dispersion district.But, in the time attaching most importance to ED district, also there is amendatory space.

The object of the invention is to, the fluorphosphate glass with ED and excellent stability is provided, each freedom glass material, optical element blank and optical element and manufacture method thereof for compression molding that above-mentioned fluorphosphate glass forms are provided, and the manufacture method of the glass forming body that comprises above-mentioned glass is provided.

The means of dealing with problems

For achieving the above object, the present inventor conducts in-depth research.As a result, have been found that and can obtain in the following manner the fluorphosphate glass with ED and excellent stability: improve O in fluorphosphate glass ^2-with respect to P ⁵⁺ratio (O ^2-/ P ⁵⁺) to reduce as the P of network forming component ⁵⁺content and improve as the Al of another network forming component ³⁺content, thereby suppress its volatility.Find based on this, the present invention is accomplished.

,, according to the present invention, provide

[1] fluorphosphate glass, described fluorphosphate glass comprises as glass ingredient:

The P of 3 positively charged ion %～25 positively charged ion % ⁵⁺,

Exceed 30 positively charged ion % and be the Al below 40 positively charged ion % ³⁺,

The Li of 0.5 positively charged ion %～20 positively charged ion % ⁺with

F more than 65 negatively charged ion % ^-; And

There are 700 DEG C of following liquidus temperatures;

[2] fluorphosphate glass as described in above [1], described fluorphosphate glass comprises and represents with positively charged ion %

0%～15% Mg ²⁺,

5%～35% Ca ²⁺,

5%～25% Sr ²⁺,

0%～20% Ba ²⁺,

0%～10% Na ⁺,

0%～10% K ⁺with

0%～5% Y ³⁺;

[3] fluorphosphate glass as described in above [1] or [2], described fluorphosphate glass has 85～98 Abbe number ν d;

[4] a compression molding glass material, described glass material comprises the fluorphosphate glass as described in any one in above [1]～[3].

[5] optical element blank, described optical element blank comprises the fluorphosphate glass as described in any one in above [1]～[3].

[6] optical element, described optical element comprises the fluorphosphate glass as described in any one in above [1]～[3].

[7] manufacture method for glass forming body, described method comprises by frit melting with by the glass of obtained melting injects mould so that described glass ware forming is body formed, wherein

Described frit is mixed and melting to the fluorphosphate glass in above to obtain [1]～[3] described in any one.

[8] manufacture method for glass material for compression molding, described method comprises that processing is by glass forming body as described in the method manufacture described in above [7].

[9] manufacture method of glass material for a kind of compression molding, described method comprises: in molten raw, the glass of obtained melting is flowed out, melten glass agglomerate is separated with the glass flows of melting and the process of cooling described melten glass agglomerate in, frit is shaped to the preformed member for accurate compression molding, wherein

[10] manufacture method for optical element blank, described method comprises the heating of compression molding glass material, the softening and compression molding of manufacturing by compression molding glass material described to above [4] or by above [8] described method.

[11] manufacture method for optical element blank, described method comprises raw materials melt; The glass of obtained melting is flowed out; Melten glass agglomerate is separated with the glass flows of melting; With by the compression molding of described melten glass agglomerate, wherein

[12] manufacture method for optical element, described method comprises grinding and polishing by the optical element blank of above [10] or [11] described method manufacture.

[13] manufacture method for optical element, described method comprises the heating of compression molding glass material and the accurately compression molding that utilize pressing mold to manufacture by compression molding glass material described to above [4] or by above [9] described method.

[14] manufacture method of the optical element as described in above [13], is wherein incorporated into described compression molding in described pressing mold with glass material, and described glass material is heated together with described pressing mold carry out described accurate compression molding.With

[15] manufacture method of the optical element as described in above [13], wherein described compression molding is heated with glass material and be incorporated into through in the described pressing mold of preheating to carry out described accurate compression molding.

Invention effect

According to the present invention, can provide the fluorphosphate glass with ED and excellent stability.

Glass material, optical element blank and optical element and the manufacture method thereof for compression molding of each self-contained above-mentioned fluorphosphate glass can also be provided in addition.The manufacture method of the glass forming body that comprises above-mentioned glass also can be provided in addition.

Embodiment

[fluorphosphate glass]

Fluorphosphate glass of the present invention is described below.

Fluorphosphate glass of the present invention is characterised in that, described fluorphosphate glass comprises

The P of 3 positively charged ion %～25 positively charged ion % ⁵⁺,

The Li of 0.5 positively charged ion %～20 positively charged ion % ⁺with

The F as glass ingredient more than 65 negatively charged ion % ^-, and there are 700 DEG C of following liquidus temperatures.

In this manual, unless otherwise noted, otherwise the content of each cation constituent and total content thereof represent with positively charged ion %, and the content of each anionic component and total content thereof represent with negatively charged ion %.About this point, contain certain component X of 0% and mean that the content of component X is 0%, also mean and do not contain component X.

Fluorphosphate glass of the present invention can also contain

0%～15% Mg ²⁺,

5%～35% Ca ²⁺,

5%～25% Sr ²⁺,

0%～20% Ba ²⁺,

0%～10% Na ⁺,

0%～10% K ⁺with

0%～5% Y ³⁺.

The reason that limits above-mentioned scope is described below.

P ⁵⁺be a kind of must composition and serve as the network former of glass.Work as P ⁵⁺content while being less than 3%, the stability of glass can be extremely deteriorated.In the time that its content exceedes 25%, the volatilization of glass ingredient becomes strongly, and result is difficult to obtain the glass of optics homogeneous or batch production and has the glass of stable optical characteristics.Therefore, P ⁵⁺content be preferably 5%～20%, more preferably 5%～15%, and then more preferably 10%～15%.

Al ³⁺be a kind of must composition and play the effect of the stability of improving glass.Al ³⁺requirement with F ^-the increase of content and increasing.At the F containing more than 65 negatively charged ion % ^-fluorphosphate glass of the present invention in, for further improving stability, must introduce and exceed 30% Al ³⁺.But, work as Al ³⁺when content exceedes 40%, the stability degradation of glass.Therefore, Al ³⁺content exceed 30% and be below 40%.Al ³⁺content be preferably 30.5%～38%, more preferably 31%～35%, and then more preferably 32%～34%.

Although Li ⁺reduced the viscosity of glass melting liquid, but it has extremely strong effect for reducing liquidus temperature.As a result, it has improved the viscosity of glass in the time of liquidus temperature, thereby has produced the effect that prevents from occurring striped when by the glass ware forming of melting.In addition, it also has the effect that reduces second-order transition temperature.Work as Li ⁺content while being less than 0.5%, above-mentioned effect is insufficient.In the time that its content exceedes 20%, the viscosity of glass melting liquid is too reduced, thereby result is difficult to moulding or causes that stability, glass is deteriorated has promoted crystallization.Therefore, by Li ⁺content be adjusted into 0.5%～20%.Li ⁺content be preferably 0.5%～10%, more preferably 1%～5%, and then more preferably 2%～5%.

F ^-it is a kind of essential composition of glass being given to low dispersivity and anomalous dispersion.Work as F ^-content while being less than 65%, be difficult to obtain required low dispersivity by becoming, and anomalous dispersion is also insufficient.Therefore, by F ⁺content be adjusted into more than 65%.F ^-it is 95% that the upper limit of content can be considered to target.F ^-content be preferably 75%～92%, more preferably 80%～85%.

Anionic component in fluorphosphate glass of the present invention mainly comprises F ^-and O ^2-.In addition, also can introduce a small amount of Cl ^-as anionic component.In the time that the glass of melting is flowed out from platinum base tube road, glass is upwards wetting on the outer surface of pipeline, causes the appearance of striped etc.But, the effect that reduces " upwards wetting (the getting wet upward) " of glass melting liquid can pass through to add Cl ^-obtain.

Just glass is had with regard to excellent stability, F ^-and O ^2-total content be preferably more than 95%, more preferably more than 97%, and then more preferably more than 98%, more preferably more than 99%.

The liquidus temperature of fluorphosphate glass of the present invention is below 700 DEG C.In the present invention, be suitable for melting glass ware forming viscosity characteristics as mentioned above by reduce liquidus temperature obtain.When liquidus temperature is during higher than 700 DEG C, the volatilization of high temp glass surface raises, and causes as there is the problem such as striped and optical characteristics variation.But, below liquidus temperature being adjusted to 700 DEG C, can reduce or solve described problem.Preferably, the liquidus temperature in the present invention is below 680 DEG C, and more preferably this temperature is below 650 DEG C.Although the lower limit for liquidus temperature does not exist special restriction, can think that target is 550 DEG C.

By being introduced into many 15% Mg ²⁺can play the effect of the stability of improving glass.Therefore, Mg ²⁺content be preferably 0%～15%, more preferably 1%～10%, and then more preferably 2%～5%.

Ca ²⁺there is the effect of the stability that improves glass, and be need to be with F ^-the increase of content and the composition that increases.Work as Ca ²⁺content while being less than 5%, be difficult to fully obtain above effect.In the time that it exceedes 35%, stability degradation.Therefore, Ca ²⁺content be preferably 5%～35%.Ca ²⁺content more preferably 10%～30%.Ca ²⁺content further preferred under be limited to 20%, and Ca ²⁺content further preferred on be limited to 25%.

Sr ²⁺there is the effect that improves stability, glass.In the time that its content is less than 5%, above-mentioned effect is insufficient.In the time that its content exceedes 25%, stability degradation.Therefore, Sr ²⁺content be preferably 5%～25%.Sr ²⁺content more preferably 10%～25%, and then more preferably 15%～20%.

As mentioned above, the stability of glass can be by making Ca ²⁺and Sr ²⁺coexist and be further improved.

By being introduced into many 20% Ba ²⁺can play the effect of the stability of improving glass.Therefore, Ba ²⁺content be preferably 0%～20%.At F ^-in the very little glass of content, Ba ²⁺there is very strong effect for improving stability.But, at F ^-the very large glass of amount in, Ba ²⁺it not essential composition.Ba ²⁺content more preferably 1%～15%, and then more preferably 5%～10%.

For further improving the stability of glass, work as F ^-amount when very large, preferably make Mg ²⁺with Ca ²⁺and Sr ²⁺coexist.Work as F ^-amount when very little, preferably make Ba ²⁺with Ca ²⁺and Sr ²⁺coexist.

Na ⁺play the effect that reduces second-order transition temperature.But its too much introducing can cause stability, glass deteriorated.In addition, its water tolerance also can be deteriorated.Therefore, Na ⁺content be preferably 0%～10%.Na ⁺content more preferably 0%～5%, and then more preferably 0%～2%.

K ⁺also play the effect that reduces second-order transition temperature.But its too much introducing can cause stability, glass deteriorated.In addition, its water tolerance also can be deteriorated.Therefore, K ⁺content be preferably 0%～10%.K ⁺content more preferably 0%～5%, and then more preferably 0%～2%.

Can be by making multiple alkali metal component Li ⁺, Na ⁺and K ⁺coexist and improve the stability of glass.

The stability of glass is expected to by introducing a small amount of Y ³⁺and improve.But in the time that its content exceedes 5%, the melt temperature of glass raises, and has promoted the evaporation from glass, therefore stability, glass also can be deteriorated.Therefore, Y ³⁺content be preferably 0%～5%.Y ³⁺content more preferably 0.5%～3%, and then more preferably 1%～3%.

In addition, for adjusting specific refractory power etc., can introduce a small amount of La ³⁺, Gd ³⁺, Zr ⁴⁺and Zn ²⁺.

About this point, there is excellent melten glass formability and the fluorphosphate glass of high-quality for obtaining, preferably P ⁵⁺, Al ³⁺, Li ⁺, Mg ²⁺, Ca ²⁺, Sr ²⁺, Ba ²⁺, Na ⁺, K ⁺and Y ³⁺total content be more than 95%, more preferably this total content is more than 97%, and then more preferably this total content is more than 98%, more preferably this total content is more than 99%.

The following describes and preferably avoid introducing the material in glass.

Pb, As, Cd, Ti, Te, Cr, Se, U and Th are not only material unnecessary in fluorphosphate glass of the present invention, are also the materials with high carrying capacity of environment.Therefore preferably they are not introduced in glass.

Fluorphosphate glass of the present invention does not need as compositions such as Lu, Sc, Hf and Ge.Because Lu, Sc, Hf and Ge are expensive compositions, therefore preferably they are not introduced in glass.

Fluorphosphate glass of the present invention has shown in the very wide wavelength zone of visibility region to have excellent transmittance.For utilizing this character, preferably, do not introduce and cause painted material as Cu, Cr, V, Fe, Ni, Co and Nd etc.

Preferably, the second-order transition temperature of fluorphosphate glass of the present invention is lower than 500 DEG C; More preferably this temperature is below 480 DEG C; And then more preferably this temperature is below 460 DEG C, more preferably this temperature is below 440 DEG C.

Because fluorphosphate glass of the present invention has lower glass transition temperatures as mentioned above, therefore this glass is suitable for accurate compression molding, and is reheated, has when softening and moulding excellent formability at glass.Because second-order transition temperature is very low as mentioned above, therefore Heating temperature when moulding can be reduced to lower.Therefore, due to glass with as the chemical reaction of the moulds such as pressing mold be difficult to generation, thereby can moulding there is clean, smooth surperficial glass forming body.In addition, the deteriorated of mould also can be inhibited.

In fluorphosphate glass of the present invention, preferably Abbe number ν d is more than 85; More preferably Abbe number ν d is 88～96; And then more preferably Abbe number ν d is 88～92.

Refractive index n d is preferably 1.43～1.5, and more preferably 1.45～1.5.

Fluorphosphate glass of the present invention has excellent stability, because liquidus temperature is below 700 DEG C and has ED.Therefore, this high-quality fluorphosphate glass can be provided as to the optical element material that is suitable for chromatic aberration correction.

About this point, with regard to suppressing the volatility and corrodibility of fluorphosphate glass, O ^2-content and P ⁵⁺mol ratio (the O of content ^2-/ P ⁵⁺) be preferably more than 3.5.

About the raw material of fluorphosphate glass, normally used is phosphoric acid salt.For improving as far as possible the fluorine (F introducing as anionic component ^-) amount, use wherein with respect to each phosphorus (P ⁵⁺) atom oxygen (O ^2-) the lower metaphosphate (Sauerstoffatom/phosphorus atom=3) of ratio (Sauerstoffatom/phosphorus atom) of atomicity.But, according to the present inventor's research, clearly find, in the time that Sauerstoffatom in the glass of melting is adjusted to more than 3.5 (Sauerstoffatom/phosphorus atom>=3.5) with respect to the atomic ratio of a phosphorus atom, the amount of the volatile component producing is fully reduced compared with following situation, described situation is: when using above-mentioned metaphosphate while preparing glass, come from the metaphosphoric acid of raw material and fluorine and in the glass of melting, react each other and produce the fluorine phosphinylidyne (POF as volatile component ₃).Its reason is considered to be, as the phosphoric acid being present in the glass of melting, wherein with respect to each phosphorus (P ⁵⁺) atom oxygen (O ^2-) ratio (Sauerstoffatom/phosphorus atom) of the atomicity bis phosphoric acid that is 3.5 is than wherein with respect to each phosphorus (P ⁵⁺) atom oxygen (O ^2-) ratio (Sauerstoffatom/phosphorus atom) of atomicity is 3 metaphosphoric acid has more high stability.Therefore, as O in the glass of melting ^2-content and P ⁵⁺mol ratio (the O of content ^2-/ P ⁵⁺) be adjusted to 3.5 when above, by the glass obtaining without metaphosphoric acid, thereby suppress the generation as the fluorine phosphinylidyne of volatile component, thus, the quality relevant to the fluctuation of glass composition changes and fully reduced, and the corrosion of melten glass is also inhibited.As a result, the appearance of the striped relevant to volatilization is reduced.In addition, the corrosion of melting crucible is also inhibited, thereby has prevented that the material that forms crucible from mixing with glass as impurity.Can obtain thus optics homogeneous, pure high-quality fluorphosphate glass.In addition the refractive index fluctuation while, manufacturing glass also can be reduced or suppress because suppressing volatilization.

About improving mol ratio (O ^2-/ P ⁵⁺) technology, can consider relatively to improve O ^2-content or relatively reduce P ⁵⁺content.In the present invention, for strengthening low dispersivity and anomalous dispersion, the F in main cation constituent ^-content need to be increased to 65 positively charged ion %.Therefore, mol ratio (O ^2-/ P ⁵⁺) by relatively reducing P ⁵⁺content and improving.

At P as above ⁵⁺in the glass that content is lowered, need to improve Al ³⁺content to keep the stability of glass.According to the present invention, Al ³⁺content be adjusted to and exceed 30%, therefore can improve mol ratio (O ^2-/ P ⁵⁺), keep liquidus temperature is below 700 DEG C simultaneously.Preferably mol ratio (O ^2-/ P ⁵⁺) be more than 3.4, more preferably this mol ratio is more than 3.5, and then more preferably this mol ratio is more than 3.55.

[manufacturing the method for fluorphosphate glass]

Fluorphosphate glass of the present invention can be manufactured by scorification.An example of scorification is described below.Use corresponding to phosphoric acid salt and the fluorochemical etc. of glass ingredient as frit, weigh the weight of these raw materials and it is fully mixed, to form mixing raw material.Mixing raw material is placed in to platinum crucible, and the temperature heating and melting of 850 DEG C～950 DEG C approximately 1 hour～3 hours.By the glass clarifyingization of thus obtained melting and the glass that homogenizes to obtain melting, then casting cooling rapidly in mould, makes fluorphosphate glass thus.

[compression molding glass material]

Compression molding glass material of the present invention is described below.

Compression molding glass material of the present invention is the glass material that comprises above-mentioned fluorphosphate glass of the present invention.

The molded agglomerate with glass of above-mentioned glass material finger print.The example of glass material comprises the glass agglomerate corresponding to compression molding part quality, as preformed member or optical element blank compression molding glass gob for accurate compression molding.

Above-mentioned each example is described below.

Accurately compression molding preformed member (below sometimes referred to as preformed member) refers to be heated and for the accurate glass preformed member of compression molding.Accurate compression molding as used herein is also referred to as mould optics well known in the art moulding, and is a kind of method that molded surface by transfer printing pressing mold forms the optical function surface of optical element.About this point, optical function surface refer in optical element to the light of need control reflect, the surface of reflection, diffraction or I/O, and lens surface in lens or corresponding to the surface of optical function surface.

For improving glass along the extension of molded surface and preventing that glass from react and fusing with the molded surface of pressing mold when the accurate compression molding, preferably use contains carbon film and applies the surface of preformed member.About containing carbon film, preferably using the carbon that contains as the main component film of (in the time that constituent content in film represents with atom %, carbon content is greater than the content of other elements).Particularly, the example comprises carbon film and hydrocarbon film etc.About the method forming containing carbon film, can use as currently known methodss such as vacuum deposition method, sputtering method or ion plating methods, these methods are used carbon raw material; Or utilize as the thermolysis of the unstripped gass such as hydrocarbon.

For example, because many accurate compression molding parts (, optical element) have the rotation axes of symmetry as lens, therefore need, the shape of preformed member is the shape with rotation axes of symmetry.As its specific examples, that can point out has spherical or has a shape of a rotation axes of symmetry.About the shape with a rotation axes of symmetry, existence has level and smooth skeletal lines and in the cross section that comprises above-mentioned rotation axes of symmetry, there is no angle or there is no the shape caving in, for example, there is elliptic wheel profile and the oval minor axis shape consistent with rotation axes of symmetry in above-mentioned cross section wherein.The example also comprises shape by spherical flattening is formed (by determining an axle by spherical center and shorten the shape that its size forms in the direction of above-mentioned axle).

The compression molding glass gob of optical element blank is that compression molding goes out the glass agglomerate using need be trimmed to the optical element blank of optical element by grinding and polishing time.The shape that optical element blank has is the finishing allowance that the additional plan of the shape of required optical element is eliminated by grinding and polishing, is also similar to the shape of optical element shape.

Compression molding of the present invention comprises the fluorphosphate glass with excellent stability with glass material, thereby can obtain high-quality compression molding part, even in heated situation, also there will not be devitrification at glass material during in compression molding.

[manufacture method of glass forming body]

The manufacture method of glass forming body of the present invention is described below.

The manufacture method of glass forming body of the present invention is the glass forming body manufacture method comprising the steps: molten raw, thereby and the glass of obtained melting injected to mould make glass ware forming body formed,

Wherein, by frit mix and melting with acquisition the invention described above fluorphosphate glass.

According to the present invention, owing to having used the fluorphosphate glass with excellent stability, therefore reduce or prevented the appearance by the striped causing from the volatilization of high temp glass surface, and having prevented devitrification.Can manufacture thus high quality glass formed body.

About the equipment for melten glass, can use the known equipment for melting fluorphosphate glass.Mixing and the melting of frit are as noted before.

About mould, can suitably use known mould according to forming shape.For example, can by have smooth bottom surface and three sidewalls mould (described bottom surface three sides by described three sidewalls around, a side is open) be arranged on pipeline below in the mode of bottom surface level, the glass of melting can flow out by described pipeline.Then,, by using the part of glass-filled by side walls enclose, make the glass flows of the melting of flowing out continuously from pipeline to the bottom surface of mould, and be shaped to tabular.The glass of moulding at the uniform velocity along continuous straight runs pulls out from above-mentioned opening, has certain width and certain thickness sheet glass thereby obtain.The sheet glass being drawn out is by statu quo being annealed by annealing furnace with speed slowly.Cut off the sheet glass of annealing perpendicular to pull-out direction, thereby obtain the sheet glass with desired length.

Can replace above-mentioned mould, the mould with through hole is arranged on and flow out pipeline below towards the mode of vertical direction with through hole, and the glass of melting is flowed in through hole continuously.Thereby the glass in ostium rapidly cooling be shaped to bar-shaped, and at the uniform velocity to be pulled out the bottom opening of through hole downwards.Make the glass stick pulling out from mould by being heated to the air of the second-order transition temperature that approaches glass, to make the surface temperature of glass stick approach the operation of its internal temperature, then cut off in the horizontal direction glass stick, to obtain the glass stick with desired length.

Can be to thus obtained glass forming body by hereinafter described processing to prepare compression molding glass material, or can or cut off to prepare sheet glass by its cut-out, described glass material or sheet glass can be polished or polishing, thereby obtain such as the optical element such as lens and prism.

[manufacture method of glass material for compression molding]

Compression molding of the present invention is characterised in that by the first manufacture method of glass material, and the glass forming body of the manufacture method manufacture to the glass forming body by the invention described above is processed.

For example, by cutting off or cutting off, above-mentioned sheet glass or glass stick are divided in flakes, and by these sheet glass tumbling polishings to carry out quality adjustment, thereby obtain an optical element blank of required quality.By the edge of tumbling polishing sphering sheet glass, this can remove and in the time of compression molding, cause fracture or folding edge.In addition, make the surface roughening of glass material, this can easily make to be applied to surperficial powdered mold release agents and adhere to equably from the teeth outwards in the time of compression molding.

Thereby another example is the method that grinding and the above-mentioned sheet glass of polishing obtain accurate compression molding preformed member, thereby another method is the method that obtains accurate compression molding preformed member by smooth the surface finish of the object through above-mentioned tumbling polishing.

Compression molding of the present invention is the compression molding glass material manufacture method comprising the steps by the second manufacture method of glass material: frit is shaped to the preformed member for accurate compression molding in the process of molten raw; The glass of obtained melting is flowed out; Melten glass agglomerate is separated with the glass flows of melting; With cooling melten glass agglomerate,

In the method, the melten glass agglomerate of extra fine quality separates with the glass of melting, and cooling with moulding preformed member, and the quality of described preformed member equals the quality of described melten glass agglomerate.For example, the melten glass that makes the homogeneous obtaining by melting, clarificationization and the frit that homogenizes flows out from the nozzle of the controlled temperature that made by platinum or platinum alloy.The in the situation that of moulding small size preformed member or spherical preformed member, the glass of melting drips from mass flowing nozzle as the glass drop of the melting with required quality, then by preformed member mould is received and be shaped to preformed member.

Manufacturing large and medium-sized preformed member in the situation that, the glass flows of melting is flowed down from flow out pipeline, the leading edge of the glass flows of melting is received by preformed member mould, thereby forms a constriction between the nozzle of the glass flows of melting and preformed member mould.Afterwards, preformed member mould is directly fallen suddenly, the glass flows of melting is separated in constriction by the surface tension of the glass of melting.The melten glass agglomerate with required quality is received and is shaped to preformed member by receiving-member.

In above-mentioned any method, for manufacture there is no flaw, stain, fold and a surface deterioration etc. (for example there is smooth surface, free surface) preformed member, preferably by thereby melten glass agglomerate being applied blast etc. and is made the method for its floating moulding preformed member above preformed member mould, with by the glass drop of melting is placed in to liquid medium and the method for moulding preformed member, described liquid medium is to liquefy by the material for gas under cooling normal temperature and pressure, for example, be liquid nitrogen.

Providing make the floating and moulding preformed member of melten glass agglomerate in the situation that, melten glass agglomerate is blown (being called floating gas), it is applied to blast upwards.In the case, in the time that the viscosity of melten glass agglomerate is too low, floating gas can enter glass and be retained in preformed member as bubble.But in the time that the viscosity of melten glass agglomerate is adjusted to 3dPas～60dPas, floating gas can make melten glass agglomerate floating and do not enter glass.

The example of the gas using when preformed member is blown to floating gas comprises air, N ₂gas, O ₂gas, Ar gas, He G&W steam etc.In addition, blast is not particularly limited, as long as preformed member can be floating and do not contact with the solid such as such as die surface.

The surface of the preformed member of manufacturing thus also can be coated with containing carbon film and use.

According to the first and second manufacture method of glass material for compression molding, the glass material of devitrification not can production compression molding time, because described glass material is by the glass manufacture with excellent stability.

[optical element blank and manufacture method thereof]

Optical element blank of the present invention is described below.

Optical element blank of the present invention is characterised in that, it comprises above-mentioned fluorphosphate glass of the present invention.

Optical element blank is the glass blank that is modified to as mentioned above optical element by grinding and polishing, and the shape having is the finishing allowance that the additional plan of the shape of required optical element is eliminated by grinding and polishing, be also similar to the shape of optical element shape.

The manufacture method of optical element blank of the present invention is described below.

The first manufacture method of optical element blank of the present invention is also referred to as reheating compression molding, is a kind of method of compression molding glass material heating of manufacturing to the compression molding of the invention described above glass material or by method of the present invention, softening and compression molding.

Before heating, on the surface of glass material, apply as powder release agents such as boron nitride equably, and glass material is placed on heat-staple dish and puts into thermoplastic stove.Be heated to glass softening after, glass is introduced to compression molding in pressing mold.Then, from mould, take out compression molding part, and annealing is to eliminate distortion, carries out the adjustment of optical characteristics, being adjusted into desirable value as optical characteristics such as specific refractory poweres.Can manufacture thus optical element blank.

The second manufacture method of optical element blank of the present invention is also referred to as direct compression molding, it is the optical element blank manufacture method comprising the steps: fused raw material, the glass of obtained melting is flowed out, melten glass agglomerate is separated with the glass flows of melting, with by the compression molding of melten glass agglomerate, wherein frit is mixed and melting, to obtain the fluorphosphate glass of the invention described above.

First, the glass flows that makes the melting homogenizing is to being coated with as on the molded surface of the counterdie of the powder release agents such as boron nitride equably, and uses the glass flows of the cutting knife that is called scissors supports lower end melting by counterdie to cut off therebetween.Thus, on the molded surface of counterdie, obtained the melten glass agglomerate of required quality.Then, the counterdie that is equipped with melten glass agglomerate on it is directly transferred to the patrix that sets in another location below, use upper die and lower die to the mold pressing of melten glass agglomerate to be shaped to the shape of optical element blank.Next, from mould, take out compression molding part, and annealing is to eliminate distortion, carries out the adjustment of optical characteristics, being adjusted into desirable value as optical characteristics such as specific refractory poweres.Can manufacture thus optical element blank.

Above-mentioned two kinds of methods all can be carried out in air.Place dish of preformed member etc. thereon about material, thermoplastic stove and the heating of condition of molding, pressing mold with when softening, can adopt any known conditions and object.

According to the present invention, can provide and can produce the optical element blank and the manufacture method thereof that do not have such as the optical element of the defect such as devitrification and striped.

[optical element and manufacture method thereof]

Optical element of the present invention is described below.

Optical element of the present invention is the optical element of the fluorphosphate glass that comprises the invention described above.Its specific examples comprises: lens, as non-spherical lens, spherical lens, plano-concave lens, plano-convex lens, biconcave lens, biconvex lens, male bend moon-shaped lens and recessed meniscus shaped lens; Microlens, lens arra, lens with diffraction grating, prism and with the prism of lens function etc.Can on the surface of optical element, form as required anti-reflective film or there is the part reflectance coating of wavelength selectivity.

Optical element of the present invention comprises the glass with low dispersivity and positive anomalous dispersion, therefore by carrying out the chromatic aberration correction of high-grade (high order) with the optical element combination being made up of other glass.In addition, because optical element is included in whole visible region and all shows the glass of high transmission rate, therefore the color balance of transmitted light can be not deteriorated.In addition, described optical element is also applicable to the lens that conduct or collect short wavelength's light.Optical element of the present invention can suitably be used as the optical systems such as the imaging optical system of formation such as various cameras (as digital still life camera, digital video camera, film type camera, monitoring camera and vehicle-mounted camera etc.), or the optical element of the projection optical system of liquid crystal projection apparatus and rear projector etc.Particularly, it is suitable for the front lens of long shot.

In addition, described optical element be suitable as conduction from as the optical record medium such as DVD or CD, read or to the optical element of the light of its data writing, for example optical pickup lens or collimating lens, in addition, be also suitable as optical communication element.

The manufacture method of optical element of the present invention is described below.

The first manufacture method of optical element of the present invention is characterised in that, optical element blank grinding and polishing that the method by the invention described above is manufactured.Can be by any currently known methods for grinding and polishing.

The second manufacture method of optical element of the present invention is characterised in that, the compression molding glass material that the compression molding of the invention described above is manufactured with glass material or by method of the present invention heats and uses the accurate compression molding of pressing mold.Above-mentioned glass material as used herein refers to preformed member.

Preferably, pressing mold and preformed member heat-processed and mold process are carried out in non-oxidizing atmosphere (as the gas mixture of nitrogen or nitrogen and hydrogen), with the oxidation of the mold release film that prevents the molded surface of pressing mold or arrange on above-mentioned molded surface (releasing film).In non-oxidizing atmosphere, be coated on the surperficial not oxidized containing carbon film of preformed member, above-mentioned film is retained on the surface of the profiled member obtaining by accurate compression molding.Although this film finally must be removed, in order to be easier to and to remove up hill and dale containing carbon film, accurate compression molding part for example, can be heated in oxidizing atmosphere (air).Oxidation and removal containing carbon film should be carried out at the temperature that accurately compression molding part can not be out of shape because of heating.Particularly, preferably at the temperature lower than second-order transition temperature, carry out described oxidation and removal.

In accurate compression molding, use its molded surface to be processed as accurately in advance the pressing mold of desired shape.But, can on molded surface, form mold release film, to prevent glass melting when the mold pressing.The example of mold release film comprises containing carbon film, nitride mould and noble metal film, and preferably using hydrogenated carbon film or carbon film etc. as containing carbon film.In accurate compression molding, preformed member is provided at a pair of its relative molded surface by between moulding accurately upper die and lower die, and then, it is 10 that mould and preformed member are heated to glass viscosity ⁵dPas～10 ⁹the corresponding temperature of dPas is to soften preformed member, molded after described preformed member, thus the molded surface of mould is transferred on glass accurately.

In addition, will be preheated to glass viscosity is 10 ⁴dPas～10 ⁸the preformed member of the corresponding temperature of dPas provides between a pair of its relative molded surface is by moulding accurately upper die and lower die, and then compression molding is to be transferred in accurately on glass by the molded surface of mould.

Pressure when mold pressing and time can consider that the viscosity of glass etc. suitably determines.For example, molding pressure can be about 5MPa～15MPa, and clamp time can be 10 seconds～300 seconds.As the mold pressing parameter such as clamp time and molding pressure can suitably arrange according to the shape and size of profiled member in known range.

Afterwards, by mould cooling and demoulding with accurate compression molding part, the preferably demoulding in the time reaching the temperature that is equal to or less than deformation point, then takes out accurate compression molding part.About this point, for accurately optical characteristics being set as to desirable value, can suitably adjust the annealing conditions (for example, annealing speed etc.) of profiled member when cooling.

The second manufacture method of above-mentioned optical element can roughly be divided into following two kinds of methods.First method is following Optical element manufacturing method, wherein compression molding is introduced to pressing mold with glass material, and above-mentioned glass material is heated to carry out described accurate compression molding together with pressing mold.When focus on improve as formed precisions such as surface accuracy and excentricity precision on time, the method is recommend method.Second method is the manufacture method of following optical element, wherein glass material is heated and introduces in the pressing mold of preheating to carry out accurate compression molding.Be recommend method when focusing on the method while improving in productivity.

The second manufacture method of optical element is suitable for producing various non-spherical lenses, as recessed meniscus shaped lens, male bend moon-shaped lens, biconcave lens, biconvex lens, plano-convex lens and plano-concave lens; And compact optical element, as optical pickup lens and optical communication lens.

According to the present invention, the high-quality optical element being made by ED glass and the method for stably manufacturing above-mentioned optical element can be provided, this is because used the fluorphosphate glass with excellent stability.

Embodiment

Although will describe in further detail the present invention by embodiment below, the invention should not be deemed to be limited to these embodiment.

Embodiment 1

For obtaining the glass composition shown in table 1～table 6, use phosphoric acid salt, fluorochemical and oxide compound etc. corresponding to each glass ingredient as the raw material of introducing each composition, the weight of raw materials weighing also fully mixes to prepare mixing raw material by it.Mixing raw material is put into platinum crucible heating and melting.After melting, the glass of melting is injected to mould and makes it be cooled to second-order transition temperature.And then, this glass is placed in annealing furnace, and in the glass transition temperature range of this glass, anneals approximately 1 hour, subsequently it is cooled in stove to room temperature.Obtain thus the opticglass that is numbered 1～57.In thus obtained opticglass, do not observe under the microscope crystal settling.

The characteristic of thus obtained opticglass is as shown in table 1～table 6.

About this point, the various characteristics of opticglass by under show method measure.

(1) refractive index n d, Abbe number ν d

For by with the cooling glass obtaining of rate of temperature fall of-30 DEG C/h, use refractometry method measurement refractive index n d and the Abbe number ν d of Japanese opticglass TIA.

(2) liquidus temperature LT

In platinum crucible with cover, add 100g glass cullet, and keep 30 minutes at 950 DEG C in nitrogen atmosphere.Then, glass melting liquid is transferred to being set as in air atmosphere and does not reduce in the stove of preset temperature of the temperature of glass melting liquid, and keep 2 hours.Keep, after 2 hours, glass being taken out from stove, and making it cooling.Then, under opticmicroscope, amplify and observe this glass.Under various holding temperatures, repeat this operation, and using the minimum holding temperature that does not retain crystal as liquidus temperature.

(3) glass transition temperature Tg

Use the thermomechanical analyzer (TMA) of being manufactured by RIGAKU Corporation to measure second-order transition temperature with the temperature rise rate of 10 DEG C/min.

Embodiment 2

By prepared for obtaining frit melting, the clarificationization that each opticglass mixes and homogenizing, to produce the glass of melting in embodiment 1.The glass of this melting is dripped from the nozzle being made by platinum with the form of the glass drop of melting; It is received by preformed member mould; And make it floating and be shaped to by each the spherical preformed member forming in above-mentioned various glass by the glass of this melting being applied to blast.

In addition, the glass that makes above-mentioned melting flows out continuously from the pipeline being made by platinum, and its lower end received by preformed member mould, thereby forms constriction in the glass flows of melting.Then, preformed member mould is directly fallen suddenly, thereby cut off the glass flows of melting in constriction.The melten glass agglomerate separating is received by preformed member mould, thereby and makes its floating each preformed member comprising in above-mentioned various glass that is shaped to by this melten glass agglomerate being applied to blast.

The preformed member obtaining is optics homogeneous, and does not also observe devitrification therein.

Embodiment 3

The glass of the melting providing in embodiment 2 is flowed out continuously; Casting in mould; And be shaped to glass block.Afterwards, glass block annealed and cut to obtain multiple sheet glass.These sheet glass are ground and polishing, thereby manufacture each the preformed member comprising in above-mentioned various glass.The preformed member obtaining is optics homogeneous, and does not also observe devitrification therein.

Embodiment 4

The glass of the melting providing in embodiment 2 is flowed out continuously; Casting in mould; And be shaped to glass block.Afterwards, glass block annealed and cut to obtain multiple sheet glass.By these sheet glass tumbling polishings, to prepare each the compression molding glass gob comprising in above-mentioned various glass.The inside of the glass gob obtaining is optics homogeneous, and does not also observe devitrification therein.

Embodiment 5

On the surface of preformed member of manufacturing in embodiment 1 and 2, coating is containing carbon film, and is introduced in the pressing mold that comprises upper die and lower die and cylinder mould, described upper die and lower die made by SiC and its molded surface on be provided with containing carbon film.Pressing mold is heated to soften preformed member together with preformed member in nitrogen atmosphere to the accurate compression molding of described preformed member.Prepared thus the various lens that comprise above-mentioned various glass, these lens have aspheric surface male bend moon-shaped lens, the recessed meniscus shaped lens of aspheric surface, aspheric surface biconvex lens, aspheric surface biconcave lens and optical pickup lens.

Embodiment 6

To the powdered mold release agents that coating comprises boron nitride equably on the surface of the glass gob of manufacturing in embodiment 4, then it heat in air atmosphere and soften.Carry out compression molding with pressing mold, thereby manufacture the blank of various lens, described various lens have sphere male bend moon-shaped lens, the recessed meniscus shaped lens of sphere, sphere biconvex lens and sphere biconcave lens.So just make the lenticular blank that comprises above-mentioned various glass.

Embodiment 7

The glass of the melting of preparation in embodiment 2 is flowed out; And use the glass flows of scissors cut-out melting with fractional melting glass agglomerate.Use pressing mold to carry out compression molding to manufacture the blank of various lens, described various lens have sphere male bend moon-shaped lens, the recessed meniscus shaped lens of sphere, sphere biconvex lens and sphere biconcave lens.Make thus the lenticular blank that comprises above-mentioned various glass.The inside of the glass blank obtaining is optics homogeneous, and does not also observe devitrification therein.

Embodiment 8

The each self-annealing of lenticular blank of manufacturing in embodiment 6 and embodiment 7 is out of shape to eliminate, and specific refractory power is adjusted into desirable value, then grind and polishing to prepare various lens, described various lens have sphere male bend moon-shaped lens, the recessed meniscus shaped lens of sphere, sphere biconvex lens and sphere biconcave lens.The lens that comprise above-mentioned various glass are so just made.

Embodiment 9

Make in embodiment 2 glass of the melting of preparation flow out, and in mould casting to prepare glass block.By glass block cutting, grinding and polishing, to prepare various spherical lenses and prism.The lens that obtain and prism are optics homogeneous, and also do not observe devitrification therein.

Although described the present invention in detail with reference to the specific embodiment of the invention, it is obvious to the skilled person that and can make various changes and modifications it, and do not depart from the spirit and scope of the present invention.

No. 2008-047135th, the Japanese patent application of the application based on submitting on February 28th, 2008, by reference to its full content is incorporated in this specification sheets.

Industrial applicibility

Fluorphosphate glass of the present invention is the glass with excellent stability, glass and ED, and is applicable to manufacture glass material for compression molding (as accurate compression molding preformed member etc.), optical element blank and optical element.

Claims

1. a fluorphosphate glass, described fluorphosphate glass comprises as glass ingredient:

The P of 3 positively charged ion %～25 positively charged ion % ⁵⁺,

The Ba of 0 positively charged ion %～10 positively charged ion % ²⁺,

The Li of 0.5 positively charged ion %～20 positively charged ion % ⁺with

F more than 65 negatively charged ion % ^-.

2. an optical element, described optical element comprises fluorphosphate glass claimed in claim 1.